Study On Bottom Topography Of Ebinur Based On Remote Sensing Technology

The remote-sensing with inexpensive, rich in widely coverage, stronger actual effect, easily date acquisition etc can achieve the marco-observation of water depth . By the technique of which remote-sensing Inversion, the bottom topography of macrophytic lakes in concerning the factors of the wide water region, shallow water, changeable water level , inconvenient located arid area can be conducted dynamic monitoring with image size.This paper based on the theory of remote-sensing for water, by actually measuring water depth and ASTER images correlation analysis, confirmed that the best wave band of the water depth on ASTER inversion Ebinur lake is band one (0.52-0.60μm), constructed a water depth of remote sensing inversion model Z = 2.5983x~2—57.069x +312.98,"x"is bond , one of natural logarithms. The inversion indicate that the modelcan be used in Remote Sensing inversion of Ebinur lakes in the average water depth of lake 0.94m,the deepest is 3.68 m . Those have been already proved by practice measure water depth. The absolute value error is 0.03m .The lake surface depth deducts the water depth. Building a whole lake bottom topography DEM and getting the result by analyzing the spare as following :The lake have the 38 piece of sand bar in the over 850 meters lengthier in whole lake. Bortala River estuarine delta covers 0.39 km~2. The two anabranch of Jin river formed fan shape estuary delta, in which one is large and another one is small, those are 0.23,0.79km~2.The Ebinur lakes water storage is 8.26 hundred millions m~3 ,Building the storage model on water level : V = 1.0241h2 - 381.08h + 35,R2 = 0.9994,h≤189. and V= 5E-05 S~2 - 0.0091 S + 0.5316,R2 = 0.9846,S< 550, V is storage capacity(hundred million m~3),S is water surface area(km~2),H is height of the water level(m).Showing the condition of the lake atrophy when the height of the water level is 188.38m, water surface area 450 km~2, storage capacity is 3.91 hundred millions m~3, the maximum value of water depth is 3.68m, minimum is 0.06m,mean is 1.85m. The east-south part of the lake is show off. in witch it will change to the area 67.68 km~2, the shape looks like crescent dry bottom. When the height of the water level is 187.00m,water surface area 189.84km~2 ,the storage capacity is 0.81 hundred millions m~3,the maximum value of water depth is 3.60m, minimum is1.18m,mean is 2.43m.The average lake drop to the point (655981,4971925 )is as a lake center the long axis is 23.5Km,short axis 7.7Km.within ellipse area(the elevation 185.52—187.00m) and along the Bortala river, Jin river banks, the average lake drop to main hollow under water . When the height of the water level is186 m water surface area 10.96 km~2 ,the storage capacity is0.03 hundred millions m~3, the maximum value of water depth is 3.51m, minimum is 2.61m,mean is 2.61m. lake is almost dry.The maximum gradient is 1.46~0, average one 0.16~0, standard deviation is 0.16~0,at short axis direction in bottom topography section. At long axis direction, the maximum gradient is 1.23~0,average one0.13~0, standard deviation is 0.11,all the statistical summary shows that the short axis direction NS is bigger than the long axis EW, which indicate that the fluctuate of bottom topography is bigger and more crisp in short axis direction, those also fully prove that the main power of long axis direction EW that build the bottom come from Alataw Pass that is prevalence north.